Ball lightning is an odd phenomenon. The few, fortunate people who have seen an incident describe the lightning as a roughly spherical glowing object that travels horizontally for a few seconds before vanishing. However, while several experiments have reproduced something resembling the phenomenon, the physical mechanism behind ball lightning is somewhat mysterious.

Now, a team of researchers serendipitously observed ball lightning at a time when they had the right equipment to study it. Jianyong Cen, Ping Yuan, and Simin Xue were in the field measuring the properties of ordinary lightning when they happened to catch ball lightning with both their high-speed cameras and their spectrographs. They found the chemical composition of the event matched that of soil. That strongly supports the hypothesis (proposed nearly fifteen years ago) that ball lightning is basically a dirt clod dislodged and heated to incandescence by a cloud-to-ground lightning strike.

High-speed video footage of ball lightning with its measured spectrum.

Ordinary lightning occurs due to the ionization and dissociation of molecules in the air (a process with the awesome name "dielectric breakdown"), which occurs during a static electric discharge between clouds and the ground. Ball lightning is much rarer, to the point where some have even postulated it's actually a hallucination rather than a real weather phenomenon. As the name suggests, it appears as a spherical or spheroidal ball of light, between one centimeter and one meter in size, and variously colored as purple, green, white, or orange.

Just like normal lightning, ball lightning seems to occur primarily during thunderstorms. These events persist a few seconds, and the spheres travel horizontally close to ground level.

That information primarily comes from eyewitness accounts; ball lightning is rare enough that no scientists have ever observed it in the field while they had equipment to measure its properties. At least not until the summer of 2012, when the authors of the new paper were out on the Qinghai Plateau in China during a thunderstorm, taking spectral readings of ordinary cloud-to-ground (CG) lightning.

Just a few minutes before midnight, the researchers' digital video cameras picked up a ball lightning event, evidently originating from the location of a lightning strike. By estimating the distance to the strike (including the method many of us learned as children: counting the time between the flash of light and the sound of thunder), they determined the sphere was as much as 8 meters in diameter at its greatest size. They also estimated its speed to be about 8.6 meters per second (19 miles per hour). The whole event lasted roughly 1.12 seconds.

At its origin, the ball was a bright white-violet in color, but then it faded to orange and then red before vanishing. Analyzing the spectrum, the researchers identified silicon, iron, and calcium—three of the major chemical components in soil. (Aluminum is another common element in soil, but the authors pointed out that their cameras weren't able to spot the appropriate wavelengths to identify it.) Unfortunately, their equipment was insufficiently sophisticated to measure the ball lightning's temperature, but based on the incandescent properties, it was likely between 15,000 and 30,000° C.

The chemical signature of soil particles in the ball lightning lends strong support to an idea proposed by J. Abrahamson and J. Dinniss in 2000. They noted that silicon compounds, when heated to extreme temperatures, ejected fireballs not unlike ball lightning. K. D. Stephan and N. Massey reported that they could reproduce at least some of the reported properties of ball lightning by producing molten silicon spheres.

Given the physical picture from the Qinghai observation and the experiments, the hypothesis seems plausible. A cloud-to-ground lightning strike heats a spot on the ground to high temperature, ejecting a bunch of hot particles from the soil, which glow in the characteristic way. These spheres cool and dissipate over a period of a few seconds, all while moving quickly across the ground. While this picture may not be true for all ball lightning, it's the first plausible and coherent explanation for a weird, rare phenomenon.

I remember as a kid reading a real-life ghost stories book in which people described this phenomenon, which they had attributed to demons or an evil spirit. Nice to see a rational explanation with some scientific backing!

With so much unexplained, it's no wonder that decades of past were littered with stories of paranormal activities, and rife with exorcisms!

This doesn't seem to account for the classical description of ball lightning: usually indoors and moving.

I second that. There may also be another phenomenon that doesn't involve dirt yet produces the same result. I've read stories about lightning balls appearing inside the cabins of moving aircraft, floating down the aisle without discharging directly on anyone or anything, then vanishing. I've also read stories about them appearing in houses. Full disclosure: these stories were from Readers Digest and I read them as a kid. Some shit just stays with you.

This doesn't seem to account for the classical description of ball lightning: usually indoors and moving.

I second that. There may also be another phenomenon that doesn't involve dirt yet produces the same result. I've read stories about lightning balls appearing inside the cabins of moving aircraft, floating down the aisle without discharging directly on anyone or anything, then vanishing. I've also read stories about them appearing in houses. Full disclosure: these stories were from Readers Digest and I read them as a kid. Some shit just stays with you.

My girlfriend actually has a personal ball lightning story, along the same lines as all the others. Those seem to fit much more neatly in with the induced hallucination idea referenced above.

This doesn't seem to account for the classical description of ball lightning: usually indoors and moving.

The [relatively slow] movement would be consistent with the movement of what is effectively a cloud of vapour. Either with normal ambient air currents present or the product of the soil's initial vapourization.

Years ago when my dad was stationed in Nebraska, I would see these relatively tall stands of what looked like dirt in the fields. Turns out the first stroke of lightning is often the stroke up and the electrons in the bolt would drag topsoil up with them and partially sinter or fuse the dirt. The next rainstorm will often dissolve them. Farmers would just knock them over and break them up. So it makes a lot of sense that dirt might help form ball lightning especially if there was a strong ground wind.

This doesn't seem to account for the classical description of ball lightning: usually indoors and moving.

I second that. There may also be another phenomenon that doesn't involve dirt yet produces the same result. I've read stories about lightning balls appearing inside the cabins of moving aircraft, floating down the aisle without discharging directly on anyone or anything, then vanishing. I've also read stories about them appearing in houses. Full disclosure: these stories were from Readers Digest and I read them as a kid. Some shit just stays with you.

I don't know about ball lightning in houses. Most cases I've heard of were from pilots, but planes get struck by lightning far more often then we care to think.

Yep, every commercialjet gets hit about once per year, and usually the passengers don't even realize it happened. Thanks to good engineering, the fuselage directs all the energy around them harmlessly.

I don't with to badmouth anyone, but I would take this research report with a grain of salt. Chinese researchers are known to be under extreme pressure to show results, even breakthrough results. And much of the discovered scientific misconduct over the last few years has been committed by Asian researchers. They just happened to see this when their instruments were turned on, did they?

Futhermore it confirms the theoretical and lab work done in 2000. But no copper spectral signature? Hmm..

In the absence of any actual evidence of fraud, this just comes across as xenophobia.

I remember as a kid reading a real-life ghost stories book in which people described this phenomenon, which they had attributed to demons or an evil spirit. Nice to see a rational explanation with some scientific backing!

With so much unexplained, it's no wonder that decades of past were littered with stories of paranormal activities, and rife with exorcisms!

There are studies into this sort of thing that suggest part of our fight or flight response is to anthropomorphize danger, in order to better asses what our appropriate response should be. Puts a whole new perspective on the Greek idea of "there's a dude up in the sky hurling lightning bolts!" or any deity, really.

Unfortunately this happens with most science videos on youtube. Probably why people in general are so confused about what science is and what scientist really do.

This happens with most videos on YouTube. They made a change a year or two ago that basically pushes unrelated content. The explanation I vaguely remember convincingly explained that the change was ad-revenue related. At any rate, it's irritating to be watching/listening to something and see several "MOST EPIC FAILS 2013!!!" with a thumbnail of a busty woman as the related content. Like I couldn't find that on my own.

Unfortunately this happens with most science videos on youtube. Probably why people in general are so confused about what science is and what scientist really do.

I've seen some science videos pop up as related to "Let's Plays" too, so it goes the other way as well. In particular I recall watching an Assassin's Creed MP video and finding a "related video" at the end that was all about how various alkali metals react with water (with explanations for why, they weren't just blowing things up).

I don't with to badmouth anyone, but I would take this research report with a grain of salt. Chinese researchers are known to be under extreme pressure to show results, even breakthrough results. And much of the discovered scientific misconduct over the last few years has been committed by Asian researchers. They just happened to see this when their instruments were turned on, did they?

Futhermore it confirms the theoretical and lab work done in 2000. But no copper spectral signature? Hmm..

Explained in the article:

Quote:

(Aluminum is another common element in soil, but the authors pointed out that their cameras weren't able to spot the appropriate wavelengths to identify it.)

I know of several people who have been knocked on their butt by ball lightning inside an aircraft (although it is possible it was a cloud of static electricity but then again "what is ball lightning" really seems to be the main topic of discussion). In older versions of some U.S. Navy aircraft it was possible to create a ball of electricity in the central passageway by closing a curtain across the front end of the passageway while flying through a thunderstorm. Once the charge built up the pilots would call a new unsuspecting crewmember to the front of the plane and when the curtain was opened it released the ball of electricity on the unsuspecting crewmember. The ball normally dissipated when it reached the aft end of the passageway.

Of course we also did silly things like throwing charged capacitors to unsuspecting techs as well so...

My grandma used to tell me this story when I was a little kid about a house being hit by lightning and the lightning coming out of the wall socket in the form of a ball of fire and that they had to open the door to let it out.

... so ok, I'm guessing some of that is a bit far fetched

In any case I had forgotten the story until a month or so ago when I remembered and ran it through all the things I know now and had written it all of as untrue. I guess now some of it might have truth to it.

It's definetly NOT the only explanation because ball lightning happened inside jetliners, where the dirt ball couldn't come from outside. To me it's much more likely to be gaseous than solid. Now do you want your own ball lightning ? Here's how to do it (with a bit of caution):A few years I was very interested in ball lightning and I discovered that some scientists could make them at will by bombarding a carboneous gas with micro-waves (it should still be online). And I found on the Internet how to DIY... so I did. Here's how (read the cautions before trying)...1- get a micro-wave oven, a match, a lighter and a small piece of bread, or anything else where you can stick the match to make it stand vertically.2- place the match (standing up) in the center of the oven3- light the match with the ligther, blow it as soon as the head if burned, and quickly shut the oven's door to start it (it's faster if it starts automatically when the door if closed)

Result: blowing the match makes a lot of smoke full of carbon than can be micro-waved, and what you get is...- a lot of noise... the noise that you hear when you forget a metallic spoon in the oven, which is basically the noise of an electric arc out of a Tesla coil.- a "cloud lightning", which is "ball lightning" but cloudy, not spherical... anyway it's plasma (ionized gas), one of the four fundamental states of matter.

Caution 1: I've done this with at least 4 different micro-wave ovens and one didn't survive. Caution 2: I have no idea whether this could be dangerous or not depending or the MW model. Check the net to see if there's more on this experiment.Caution 3: I've always opened the door after a few seconds because I didn't know if it was hot or not, but apparently it wasn't... no heat or burns was found (although I never measured). Be VERY cautious on how long you make it last (since you can repeat it instead).

Now, is this phenomenon exactly the same as ball lightning ? I don't know, but to me ball lightning is clearly more some kind of magnetical convection of plasma gas than levitating mud.

To me it's much more likely to be gaseous than solid....<I, I don't even want to get into this>...I don't know, but to me ball lightning is clearly more some kind of magnetical convection of plasma gas than levitating mud.

Dirt at 13K C isn't a solid. At that point it unlikely to be even a liquid anymore. SI, For example, boils around 4K C.

I wonder if the evidence rules out the alternative possibility that ball lightning is a different phenomenon that incidentally picks up dirt when it is near the ground. Any hot plasma (lightning or otherwise) would pick up particles of soil and burn them like an old-school emission spectrometer, producing the same spectral lines that these researchers captured. So maybe the ball lightning would have been there anyway, but it happened to burn some dirt because there was dirt nearby.

Or maybe ball lightning on the ground is a different phenomenon than ball lightning in the air, and they just look similar coincidentally. A single measurement can open as many mysteries as it solves!

My mother told me she witnessed ball lightning in Kuwait in 1977/78. She'll be pleased to know scientific doubt in this phenomenon has been undermined! It really is quite insulting to tell sober people that they were probably just hallucinating, just because we don't understand what they claim to have seen...

I remember as a kid reading a real-life ghost stories book in which people described this phenomenon, which they had attributed to demons or an evil spirit. Nice to see a rational explanation with some scientific backing!

With so much unexplained, it's no wonder that decades of past were littered with stories of paranormal activities, and rife with exorcisms!

There are studies into this sort of thing that suggest part of our fight or flight response is to anthropomorphize danger, in order to better asses what our appropriate response should be. Puts a whole new perspective on the Greek idea of "there's a dude up in the sky hurling lightning bolts!" or any deity, really.

I think "anthropomorphise" is the wrong word here. It's more basic than that. There's an instinctual response to presume that any unidentified phenomena are caused by an entity. As an instinctual cognitive response, this is adaptive because if you react to unidentified sights/smells/sounds/etc. as if it were a predator possibly hunting you, this will cause you to avoid some of the ones that reall are predators hunting you.

You can observe evidence of the same behavior in cats and dogs. They may not believe in gods, but they assume the existence of dangerous entities on just as little evidence as we do.

I believe I might have seen ball lightning once, over a paved road. However I did not see a noticeable amount of "travel". What I saw was lightning strike outside my house, and an instant later, an orb not terribly large, less than a meter above the pavement, which lasted just long enough for me to register that I had seen it. To this day I wonder if it was "really" there, or some artifact of my eyes from being overwhelmed by the lightning strike.

I don't with to badmouth anyone, but I would take this research report with a grain of salt. Chinese researchers are known to be under extreme pressure to show results, even breakthrough results. And much of the discovered scientific misconduct over the last few years has been committed by Asian researchers. They just happened to see this when their instruments were turned on, did they?

Futhermore it confirms the theoretical and lab work done in 2000. But no copper spectral signature? Hmm..

This issue is everywhere, known as "Publish or perish" and I don't think it was yet abolished...

I don't with to badmouth anyone, but I would take this research report with a grain of salt. Chinese researchers are known to be under extreme pressure to show results, even breakthrough results. And much of the discovered scientific misconduct over the last few years has been committed by Asian researchers. They just happened to see this when their instruments were turned on, did they?

Futhermore it confirms the theoretical and lab work done in 2000. But no copper spectral signature? Hmm..

In the absence of any actual evidence of fraud, this just comes across as xenophobia.

I wouldn't say that. I'd say it is simply wrong and evidence less. IMHO, sufficient without attribution of extra unnecessary attributes to other poster and his posts. Keep it simple.

This doesn't seem to account for the classical description of ball lightning: usually indoors and moving.

Beat me to it. This does not explain ball lightning on aircraft etc. My first “exposure” to ball lighting in print was from the Little House on the Prairie books, where Laura described what could only be ball lighting inside their dugout during a blizzard.

This doesn't seem to account for the classical description of ball lightning: usually indoors and moving.

Beat me to it. This does not explain ball lightning on aircraft etc. My first “exposure” to ball lighting in print was from the Little House on the Prairie books, where Laura described what could only be ball lighting inside their dugout during a blizzard.

Lightning during a snowstorm, AKA thundersnow, is a thing. Rare, I've only experienced it in person once, but it does exist.

As for dugouts, this doesn't really preclude it. As long as it has an electrical path in to vaporize the material, obviously dirt is present.

As for in a plane, it is unlikely to be soil there. However what is soil there but various metals with some HC and O mixed in. So another appropriate material could be the cause there.

P.S. First person descriptions can be rather dodgy on details. Especially from children.